Impact spotter bullet



Dec. 13, 1966 A. L. HITCHENS IMPACT SPOTTER BULLET Filed May 22, 1952 3,291,049 IMPACT SPOTTER BULLET Aaron L. Hitchens, North Haven, Conn., assignor to the United States of America as represented by the Secretary f the Army Filed May 22, 1952, Ser. No. 289,337 8 Claims. (Cl. 102-87) The present invention relates to a spotting and observing bullet for locating by visual observation the point of impact of the bullet.

The type of tracer ammunition now in use in the field can only be pointed at the desired target, since no means in the bullet are provided to mark its point of impact. In addition the tracer acts as a two-way tracking medium to enable enemy personnel located at the point of impact to locate the firing arm of the tracer. Spotting and observing bullets prevalent in the prior art eliminate some of the defects of the tracer type bullet. However, these bullets are also prone to detonate in midair, a defect commonly referred to as in flight functioning. In addition the prior art bullet is well known for its complexity and in the large number of parts used in its manufacture, hence it is not easily adaptable to mass production techniques. Also the arming mechanism provided has not always been effective for safe handling under normal conditions and the bullet quite often will break open when dropped to release the smoke producing agent.

It is therefore a primary objective of this invention to provide a spotting and observing bullet which is effective for locating by visual observation the point of impact, is simple and effective in design and easily adaptable to mass production techniques and which avoids objectionable in flight functioning. The bullet assembly also completely eliminates the use of lead which is a strategic material.

It is also an object of this invention to provide a spotter bullet having a hermetically sealed aluminum cup received in the bullet jacket for holding the smoke producing medium.

It is a further object of this invention to provide a spotter bullet having a simple yet effective arming mechanism for safe handling of the bullet under ordinary conditions.

It is also an object of this invention to provide a spotter bullet having a thin nosed bullet jacket wherein the thinned section is moved back from the point to a location where it is reinforced and greatly strengthened by the side wall of the aluminum capsule to resist breakage and deformation when dropped but which will rupture with the detonation produced at impact on the target, to release the smoke producing medium.

It is also a further and ancillary object of this invention to disclose a new process for loading the smoke producing medium into separate, self-contained capsules to eliminate fire hazard. This process is also adaptable to mass production techniques such as would be required for a large scale production of the spotter bullet.

With these and other objects in view which will appear as the following specification develops, reference is made to the accompanying drawing forming a part of the specification in which:

FIGURE 1 represents the spotting bullet assembly in axial section.

FIGURE 2 represents the elements which comprise the arming and firing mechanism including a brass case, firing inertia weight and priming charge.

FIGURE 3 represents the closing plug and FIGURE 4 shows the closing plug crimped in the bullet jacket.

Referring to the drawings, 1 is the bullet jacket having a standard forward ogive portion 2. The jacket has a thinned section 3, located rearwardly of the point, which is strong enough to withstand breaking open if the bullet is dropped but which will rupture on impact on the target after the bullet is fired. Received in the bullet jacket is an aluminum capsule 4 for receiving a smoke producing agent 5, such as for example white phosphorus. Other substances of similar nature exhibiting pyrophoric properties may also be used. The aluminum capsule is formed as a cup-shaped generally cylindrical member before it is forced into the bullet jacket. White phosphorus is placed in the capsule in a manner to be later described after which the open end of the capsule is covered 'wth a paper washer 4a (see FIGURE 1) to which lacquer has been applied to retain the cover in place. The capsule is then forced and press fitted into the jacket with the paper covered end in forward position so that the capsule finally assumes the shape generally of the ogival portion of the jacket. A space 6 is left between the paper covered capsule end and the jacket portion, and it is to be noted that a substantial part of the capsule is in intimate contact with the thinned portion of the jacket as at 3a to provide reinforcement and greater strength to resist breakage and deformation of the jacket. A sealing medium such as Lucolastic is provided between the aluminum capsule and the jacket to hold the capsule in place when the bullet is assembled.

The arming and firing mechanism for the bullet comprises an elongated cylindrical brass case 7 closed at its forward end 9, and struck inwardly to form a firing pin as at 10. An opening 10a is provided between the prongs forming the firing pin to permit easy fracture of the capsule when the priming mixture is detonated.

Received within the brass case is a steel inertia weight 11 grooved as at 12 and having a hollowed out forward portion 13 to receive a burster 14. A paper washer 15 is used to cover the burster 14 to prevent scratching and premature explosion of the burster in the event it contacts the firing pin inadvertently. The brass case is crimped at 16 into groove 12 in the inertia weight to form a cannelure holding the weight and burster against accidental longitudinal displacement, for example, if the bullet is dropped. The arming and firing mechanism is press fitted into the bullet jacket so that its forward end is directly adjacent an aluminum reinforcing disc 17 which is placed directly against the back end of the phosphorus containing capsule. The assembly is capped by a soft brass closing plug 18 which has a forward portion fitting into the open end of the bullet jacket. The plug is grooved as at 19 to accommodate the crimped end 20 of the bullet jacket. It will be noted that a substantial clearance exists between the rearward end of weight 11 and the forward end of plug 18. A cannelure 21 is provided in the outer peripheral surface of the jacket to receive the crimped end of the usual cartridge case (not shown) as is well known in the art.

On firing, the steel inertia weight is set back against plug 18, breaking the crimp 16 in the brass case. Thus the weight including the burster is free to slide forward upon impact. In so doing the burster engages the prongs of the firing pin at the forward end of the brass case and the explosion is sufiicient to rupture jacket 1 and capsule 4 and exposes the white phosphorus to the air. The white phosphorus ignites and burns forming a cloud of smoke. Also a slight flash of tire is produced thereby for night spotting purposes.

As indicated above the most effective and preferred smoke producing agent was found to be white phosphorus. Due to the necessity for producing the spotter bullet on a large scale and on an eflicient and effective production basis, ways and means were considered to provide a small uniform unit charge of white phosphorus for as- Patented Dec. 13, 1966 sembly into the point end of the bullet. Existing procedures were found wanting in several important characteristics since these methods handled the white phosphorus by loading it into capsules under water followed by several subsequent scrubbings with steam and water washes. This process did not lend itself to mass production techniques. Important considerations which had to be kept in mind in developing a new process were the toxic nature of white phosphorus, and its characteristic of reacting with air within a minute at ordinary room temperatures, thus presenting a considerable fire hazard.

To satisfy the requirement of mass production and at the same time mitigate the harmful effects of handling white phosphorus a loading machine was developed incorporating the following steps.

A white phosphorus rod is first immersed in a dilute copper sulfate solution to form a thin skin of copper on the surface. The rod is then picked up by tongs and inserted in a cylinder which is closed by a piston while maintaining a temperature not over 30 C. and preferably 25 C. This step eliminates the needs for melting and solidification of the white phosphorus. By means of compressed air the piston is forceably moved to extrude the phosphorus into a measuring die which is formed as a rotary type measuring valve. As the valve rotates it is moved into another position in the absence of protective atmosphere to aline with an aluminum capsule held in a rotary dial. Simultaneously a disc shaped paper blank is punched out by the machine. The white phosphorus is then pushed into the aluminum cup which is moved into proper position, the paper disc is dropped upon the cup to cover it whereupon the filled cup is moved to the next station where a lacquer cup places a drop of lacquer on the paper foil to hermetically seal the capsule. The next station crimps the cup end over slightly to hold the foil in place until the lacquer dries, after which each capsule is removed with an air jet and is now ready to be loaded into the bullet jacket. This process enables the white phosphorus to be handled in the absence of water, and since it is exposed to the air for only a fraction of a second this short time interval presents a condition which eliminates fire hazard.

The above described spotting and observing bullet is simple in design, and is admirably suited for mass production techniques because of its small number of parts. It is also safe to handle under normal conditions because of its simple but effective arming mechanism, and the bullet jacket design including the thin nosed section will immediately rupture upon impact on the target to release the smoke producing agent, but which is strong enough to withstand routine handling and inadvertent dropping. It is also constructed to eliminate the use of lead, which is a strategic material, and its over-all design and assembly is such as to eliminate in flight functioning. It is therefore apparent that I have developed a spotter bullet which is extremely effective for the intended pur pose.

Other modifications and alterations of the structure which has been disclosed herein for purposes of illus tration will be apparent to one skilled in the art, and it is obvious that the same may be made without departing from the spirit and scope of the invention as defined in the following claims:

I claim:

1. A spotting and observing bullet comprising a jacket tapering to a point at its forward end, said tapering point having a thinned out section for a portion of its length, a hermetically sealed capsule received within said tapering point having a portion of its length coextensive with said thinned out section, a smoke producing agent within said capsule, a long cylindrical case closely fitting the inside wall of said jacket and located rearwardly of said capsule, the forward end of said case struck inwardly to form a firing pin and having a hole therein, an inertia weight received within said case and having a counterbore in its forward end, a burster received within said counterbore, means detachably securing said inertia weight to said case under normal conditions whereby said inertia weight is released upon setback to move forward upon impact to thereby detonate said burster, and a rear plug for closing said jacket and said case.

2. The combination in claim 1 wherein said hermetic seal comprises a paper foil sealed with lacquer.

3. The combination in claim 1 wherein said smoke producing agent is white phosphorus.

4. The combination in claim 1 including a disc-shaped metal foil disposed between the forward end of said case and the base of said capsule to support said base when the bullet is fired.

5. The combination in claim 1 wherein said inertia weight is steel and said capsule is aluminum.

6. In a bullet for producing a visible signal on impact, a jacket comprising an ogival portion merging into a cylindrical rear portion, said ogival portion having an annular thinner wall rearwardly of the nose thereof, a sealed capsule fitting within said ogival portion and spanning said thinner wall, a case fitting said cylindrical jacket portion and having an apertured forward end extending inwardly and rearwardly to form a firing pin, a plug closing the rear end of said jacket and contacting the adjacent end of said case to hold the same against said capsule, an inertia weight guided for longitudinal sliding in and along said case, a burster secured within a recess in the forward end of said weight in cooperative relation with said firing pin, and a cannelure between said weight and case normally to maintain said burster in spaced rearward relation from said firing pin, said cannelure being broken in response to set-back in firing.

7. In a bullet for producing a visual signal upon impact with a target the combination comprising, a jacket having an ogival nose portion merging into a rear cylindrical portion, a closure for the open end of said jacket, said nose portion having an internal peripherally thinned area rearwardly of the point of the nose and forwardly of the merging portion to be ruptured upon impact with a target, a sealed aluminum capsule pressed into said nose portion in intimate contact with said area, said capsule containing white phosphorus, a cylindrical case fixedlywithin said jacket having one end abutting said closure and the other end abutting said capsule, said case having an integral apertured rearwardly and inwardly directed firing pin at its forward end, an inertia weight held rearwardly within said case against movement and spaced from said closure, said weight having its forward end recessed, a burster carried within said recessed end and spaced from said firing pin when said inertia weight is in its rearward position, said weight being released on setback to move forward on impact to fire said burster to rupture said jacket at said thinned area and expose said charge to atmosphere.

8. The device of claim 7 wherein said capsule and said forward end of the case are separated by an aluminum reinforcing disk and the forward end of said burster has a paper washer attached thereto.

References Cited by the Examiner UNITED STATES PATENTS 1,434,681 11/ 1922 Clay 102-90 2,43 6,3 78 2/ 1948 Chenoweth 1027 8 2,532,323 12/1950 Miller 10290 FOREIGN PATENTS 806,251 9/1936 France.

532,623 8/1931 Germany.

125,594 5/ 1919 Great Britain.

408,370 12/1944 Italy.

BENJAMIN A. BORCHELT, Primary Examiner. SAMUEL BOYD, Examiner. W. J. NELSON, R. F. STAHL, Assistant Examiners. 

1. A SPOTTING AND OBSERVING BULLET COMPRISING A JACKET TAPERING TO A POINT AT ITS FORWARD END, SAID TAPERING POINT HAVING A THINNED OUT SECTION. FOR A PORTION OF ITS LENGTH, A HERMETICALLY SEALED CAPSULE RECEIVED WITHIN SAID TAPERING POINT HAVING A PORTION OF ITS LENGTH COEXTENSIVE WITH SAID THINNED OUT SECTION, A SMOKE PRODUCING AGENT WITHIN SAID CAPSULE, A LONG CYLINDRICAL CASE CLOSELY FITTING THE INSIDE WALL OF SAID JACKET AND LOCATED REARWARDLY OF SAID CAPSULE, THE FORWARD END OF SAID CASE STRUCK INWARDLY TO FORM A FIRING PIN AND HAVING A HOLE THEREIN, AN INERTIA WEIGHT RECEIVED WITHIN SAID CASE AND HAVING A COUNTERBORE IN ITS FORWARD END, A BURSTER RECEIVED WITHIN SAID COUNTERBORE, MEANS DETACHABLY SECURING SAID INERTIA WEIGHT TO SAID CASE UNDER NORMAL CONDITIONS WHEREBY SAID INERTIA WEIGHT IS RELEASED UPON SETBACK TO MOVE FORWARD UPON IMPACT TO THEREBY DETONATE SAID BURSTER, AND A REAR PLUG FOR CLOSING SAID JACKET AND SAID CASE. 